Tim Farrell/The Star-LedgerDoctors diagnosed Mets second baseman Luis Castillo with a bruised right heel. NEW YORK – Amid a flurry of pre-game Mets moves, this is the most concrete: Second baseman Luis Castillo has been placed on the 15-day disabled list with a bruised right heel and 20-year-old Ruben Tejada will be the team’s everyday second baseman for “the bulk of the time,” manager Jerry Manuel said on Friday here at Citi Field.

Castillo underwent an examination on Thursday to inspect his two injured feet, and the team believes he will recover if granted enough time to rest. Tejada will replace him until he returns and center fielder Angel Pagan will move into the second spot in the batting order. But Tejada will get a shot.

“I’d just like to see what we got,” Manuel said.

***
Meanwhile, catcher Omir Santos occupied Gary Matthews Jr.’s old locker before the game began. Matthews lost the starting center-field competition to Pagan and was ineffective as a pinch-hitter (batting .190 overall). So he was designated for assignment to make room for Santos, who was catching in Double-A Binghamton.

But why did the team need Santos? Because catcher Henry Blanco is “a little banged up,” Manuel said.

Where is he injured?

“Body,” Manuel said.

“He’s just a little banged up,” Manuel continued. “I wouldn’t want to get into the specifics because it might tend to give away some of this great strategy that I have with him, you know?”

The team plans to sort out the catching situation over the next few games. That might mean a DL-stint for Blanco.

***
So right now, Jason Bay will be the team’s emergency center fielder, should Pagan leave the field. Backup Chris Carter would move to left, in that case. Bay mentioned that he played some center during the World Baseball Classic.

***
Speaking of center field . . .

Carlos Beltran batted six times as a designated hitter in an extended spring training game in Port St. Lucie. He hit two singles, but did not run the bases.

A Mets spokesman said that Beltran didn’t do anything “crazy.” The spokesman also said that these were still not considering “full baseball activities.” Beltran still has to play the field, make cuts in the outfield, run the bases, etc.

But Manuel was willing to – tentatively – punch the clock on Beltran’s return, which is supposed to take four-to-six weeks once he begins full activities:

“I do think there has to be an evaluation the day after, to see how he feels,” he said. “Whether he can continue on the same pace or progress that he’s still making. Once he starts playing and running the bases . . . I think you have to still put ‘limited.’ But at the same time, we’re getting closer to him going in and off the field in the outfield.”

***
Jonathon Niese will retake the mound, rejoin the roster and reclaim a roster spot on Saturday, when he starts against the Marlins. But Manuel did not tip his hand about who the club will demote in Niese’s place. He explained there are a variety of names still being discussed, including reliever Jenrry Mejia.

The team is still in the process of trying to convince former starter Oliver Perez to accept a minor-league assignment.

“I have no indication as far as that part of the issue goes,” Manuel said. “But we will activate Jonathon Niese. What is that subsequent move at this time, we don’t know yet.”